The invention relates to a bearing, which has a power generation unit.
The prior art discloses bearings which comprise a power generation unit in the form of a claw pole generator. The claw pole generator comprises an induction coil with an electrical conductor which is wound with a plurality of turns. In order to supply a voltage which is sufficient even at low rotation speeds, the induction coil should have a high fill factor, i.e. the electrical conductor should have as high a number of turns as possible.
U.S. Pat. No. 6,838,794 B2 describes a bearing, in particular a roller bearing, which comprises a first bearing ring, a second bearing ring and a power generation unit, which is in the form of a claw pole generator. In addition, the bearing also comprises a first claw ring fastened to the first bearing ring that has a sequence of first claws running peripherally along a circumference of the first bearing ring, a second claw ring fastened to the first bearing ring that has a sequence of second claws running peripherally along the circumference of the first bearing ring, and a magnetic induction coil, which is arranged between the two claw rings. The bearing further comprises a sequence of magnetic poles in the form of a magnet ring that run peripherally along a circumference of the second bearing ring, a magnetic induction coil, which is arranged between the two claw rings, a closed magnetic circuit that runs peripherally around the induction coil to the second magnetic pole of the magnet ring, which does not have the same name as the first magnetic pole, which is closed by a first magnetic pole of the magnet ring via a first claw of the first claw ring and via a second claw of the second claw ring. If the two bearing rings rotate relative to one another, the magnetic flux in the magnetic circuit changes since each claw is guided past a different pole. The change over time in the magnetic flux induces an AC voltage in the induction coil with a magnitude which is dependent on the number of turns in the induction coil. In order to achieve as high an induced voltage as possible, a large number of turns need to be provided for the induction coil. The induction coil is arranged in a receptacle in the form of a U in cross-section. The limbs of the U are formed by the two claw rings, and the two claw rings are magnetically conductively connected to one another by the base of the U, such that the magnetic flux is guided through the first claw in the first limb of the U of the receptacle, then through the base of the U of the receptacle and then through a second claw in the second limb of the U of the receptacle. The base of the U of the receptacle bears against the first bearing ring and reduces the amount of physical space between the two bearing rings which is available for receiving as high a number of turns of the induction coil as possible. One measurement which is proposed for increasing the number of turns of the induction coil is that of providing in each case one recess in the two opposing bearing rings and arranging the induction coil and the sequence of magnetic poles in the respective recess, with the result that the induction coil can take up an increased amount of space. For this purpose, structural changes to the two lateral surfaces of the two hearing rings are required.
US 2005/0174011 A1 describes a bearing in the form of a roller bearing which has a claw pole generator. A sequence of magnetic poles in the form of a peripherally running magnet ring are arranged in a recess in the second bearing ring, and a section of the induction coil, surrounded in cross-section on all sides by the sheet-metal cuts of the two claw rings, rests on an end face of the first bearing ring or a section of said induction coil arranged in a recess that is arranged in the lateral surface of the first bearing ring. The bearing further comprises a sensor, specifically a rotation speed sensor, to which power is applied from the claw pole generator. The sensor is arranged on the magnet ring.